From Thailand we just received once again the dwarfish brilliant redfin rasbora, Rasbora rubrodorsalis. This species was recognized as a distinct species only late, in 1997, although it is widely distributed in Southeast Asia (Laos, Cambodia, Thailand, Vietnam). It was formerly thought to be a juvenile form of the similar species Rasbora borapetensis. Unlike R. borapetensis, R. rubrodorsalis has a red spot in the dorsal fin and remains much smaller with a maximum standard length of 3 cm (not including the caudal fin). R. borapetensis grows twice as large to 6 cm standard length.
Rasbora rubrodorsalis is an excellent schooling fish for planted aquariums with Southeast Asian character. This extremely peaceful species is very adaptable. In nature the water temperatures vary seasonally in the range of below 20°C (November to February) and above 30°C (March to October). There are also no special requirements regarding the water values. Females become sexually mature at about 2 cm in length. Males are generally somewhat smaller and more delicate. In the wild, these animals are short-lived and reproduce year-round. In a scientific study that intensively studied these fishlets in Laos for a year, the oldest specimen found in the wild was 121 days old (a female), the oldest male was 92 days old, and sexual maturity sets in at around 50 days of age. In the aquarium, however, the fish grow much older, 2-3 years.
For our customers: the animals have code 452862 on our stock list. Please note that we supply only wholesale.
Text & photos: Frank Schäfer